The implication of climate change and precipitation variability on sedimentation deposits in Algerian dams

Water erosion represents a major problem in Algeria. The country loses 20 million m3 of water per year due to sediment deposits in dam reservoirs, which is related to the process of erosion in watersheds. In recent years, Algeria has seen a decrease in its average rainfall, due to the effects of climate change on water resources which have resulted in extreme droughts all over the country. The erosion in the watersheds is generally high, and the quantities of transported sediments are extremely variables. In this study, we analyzed the influence of climate change on the rate of water erosion in the watersheds through the measurement of precipitation during different time periods. Water erosion was evaluated at 21 dam reservoirs located in the northern part of the country using bathymetric surveys. Hypsometric analysis revealed that studied watersheds present several geomorphic stages: youth, mature, and old stages. The results of the study showed the influence of precipitations and its variation over time on water erosion at the studied watersheds. A strong relationship was found between average sedimentation rate and mean inter-annual precipitation.